Flood Potential Outlook
Issued by NWS Mt. Holly, NJ
FGUS71 KPHI 301859
Winter/Spring Flood Potential Outlook
National Weather Service Mount Holly NJ
259 PM EDT Thu Mar 30 2017
Winter/Spring Flood Potential Outlook...Number 7
This is the seventh in a series of annual Winter/Spring Flood
Potential Statements intended to provide insight into the
likelihood of river flooding (not flash flooding) over the
middle/lower Delaware, Lehigh, Schuylkill, Passaic and Raritan
River basins. These statements will provide information on flood
threat conditions such as recent precipitation, soil moisture,
snow cover and its water equivalent, river ice conditions,
streamflow, future precipitation and others.
This outlook does not address the severity or extent of any
future river flooding.
In the Mid-Atlantic region, heavy rainfall is the primary factor
which leads to river flooding. It is important to note that heavy
rainfall can rapidly cause river flooding any time of year, even
when the overall river flood potential is considered to be low.
This outlook is valid from March 30 to April 13, 2017.
In the Mount Holly, New Jersey Hydrologic Service Area (HSA), the
overall river flood potential is slightly above normal.
Note - For the headwaters of the Delaware River, see the
statement (FGUS71 KBGM ESFBGM) from our Binghamton (BGM) New York
CURRENT FLOODING - None.
RECENT PRECIPITATION - Below normal to above norma1. Between 3.0
and 4.5 inches of liquid have been recorded over the last 30 days.
Precipitation departure maps can be found at
www.weather.gov/marfc (under the Water Supply tab).
SNOW COVER - Normal. The snow that accumulated in early March has
melted. However, there is still snow on the ground across the
upper Delaware Basin. This snow is expected to melt and work its
way through the system (middle and lower Delaware River) over the
coming days. Depth and basin-average water equivalent estimates
can be found at www.weather.gov/marfc (under the Seasonal Interest
tab) or www.nohrsc.noaa.gov (under the National Analysis tab).
RIVER ICE - Normal. No ice has been reported across the HSA.
STREAMFLOW - Variable, much below normal to above normal. Real
time water data is available from the United States Geological
Survey by visiting http://water.usgs.gov.
SOIL MOISTURE - Normal. Soil moisture monitoring charts (Long
Term Palmer Drought Severity Index) from NOAA`s Climate
Prediction Center can be found at the following websites...
monitoring/palmer.gif as well as www.drought.gov.
GROUND WATER - USGS monitoring wells indicate that current ground
water levels across the region are variable, ranging from below
normal to above normal. Additonal information can be found at
RESERVOIR CONDITIONS - Water supply and flood control reservoirs
in the area are running below normal to normal.
FUTURE WEATHER CONDITIONS - High pressure will move offshore today.
Low pressure moving through the Ohio Valley on Friday will
redevelop near the New Jersey coast Friday night and move offshore
on Saturday. This low is expected to bring 1.00 to 2.00 inches of
rain to the area. Canadian high pressure will move into the area
for Sunday and Monday. Low pressure over the Ohio Valley on
Tuesday will move through the middle Atlantic Tuesday night and
offshore on Wednesday. More rain is expected with this low. The 8
to 14 day outlook calls for above normal temperatures and
At this time, a widespread moderate to heavy rain event is
expected Friday into Saturday. Another low could bring
additional widespread rainfall to the region early next week.
Rises are expected as a result of the rain across the Passaic,
Raritan and Rancocas Basins. Rises are also expected across the
Delaware basin including the Delaware River as a result of the
rain and snowmelt across the upper basin. A few river gauges
across the HSA are forecast to hit Action Stage this weekend.
SUMMARY - Taking all of the included variables into consideration,
the overall river flood potential is slightly above normal.
For complete weather information, visit our website at: